I'm better off trying to solve the first hurdle. This ceph cluster is in production serving 186 guest VMs. -RG
On Thu, Oct 19, 2017 at 3:52 PM, David Turner <[email protected]> wrote: > Assuming the problem with swapping out hardware is having spare > hardware... you could always switch hardware between nodes and see if the > problem follows the component. > > On Thu, Oct 19, 2017 at 4:49 PM Russell Glaue <[email protected]> wrote: > >> No, I have not ruled out the disk controller and backplane making the >> disks slower. >> Is there a way I could test that theory, other than swapping out hardware? >> -RG >> >> On Thu, Oct 19, 2017 at 3:44 PM, David Turner <[email protected]> >> wrote: >> >>> Have you ruled out the disk controller and backplane in the server >>> running slower? >>> >>> On Thu, Oct 19, 2017 at 4:42 PM Russell Glaue <[email protected]> wrote: >>> >>>> I ran the test on the Ceph pool, and ran atop on all 4 storage servers, >>>> as suggested. >>>> >>>> Out of the 4 servers: >>>> 3 of them performed with 17% to 30% disk %busy, and 11% CPU wait. >>>> Momentarily spiking up to 50% on one server, and 80% on another >>>> The 2nd newest server was almost averaging 90% disk %busy and 150% CPU >>>> wait. And more than momentarily spiking to 101% disk busy and 250% CPU >>>> wait. >>>> For this 2nd newest server, this was the statistics for about 8 of 9 >>>> disks, with the 9th disk not far behind the others. >>>> >>>> I cannot believe all 9 disks are bad >>>> They are the same disks as the newest 1st >>>> server, Crucial_CT960M500SSD1, and same exact server hardware too. >>>> They were purchased at the same time in the same purchase order and >>>> arrived at the same time. >>>> So I cannot believe I just happened to put 9 bad disks in one server, >>>> and 9 good ones in the other. >>>> >>>> I know I have Ceph configured exactly the same on all servers >>>> And I am sure I have the hardware settings configured exactly the same >>>> on the 1st and 2nd servers. >>>> So if I were someone else, I would say it maybe is bad hardware on the >>>> 2nd server. >>>> But the 2nd server is running very well without any hint of a problem. >>>> >>>> Any other ideas or suggestions? >>>> >>>> -RG >>>> >>>> >>>> On Wed, Oct 18, 2017 at 3:40 PM, Maged Mokhtar <[email protected]> >>>> wrote: >>>> >>>>> just run the same 32 threaded rados test as you did before and this >>>>> time run atop while the test is running looking for %busy of cpu/disks. It >>>>> should give an idea if there is a bottleneck in them. >>>>> >>>>> On 2017-10-18 21:35, Russell Glaue wrote: >>>>> >>>>> I cannot run the write test reviewed at the ceph-how-to-test-if-your- >>>>> ssd-is-suitable-as-a-journal-device blog. The tests write directly to >>>>> the raw disk device. >>>>> Reading an infile (created with urandom) on one SSD, writing the >>>>> outfile to another osd, yields about 17MB/s. >>>>> But Isn't this write speed limited by the speed in which in the dd >>>>> infile can be read? >>>>> And I assume the best test should be run with no other load. >>>>> >>>>> How does one run the rados bench "as stress"? >>>>> >>>>> -RG >>>>> >>>>> >>>>> On Wed, Oct 18, 2017 at 1:33 PM, Maged Mokhtar <[email protected]> >>>>> wrote: >>>>> >>>>>> measuring resource load as outlined earlier will show if the drives >>>>>> are performing well or not. Also how many osds do you have ? >>>>>> >>>>>> On 2017-10-18 19:26, Russell Glaue wrote: >>>>>> >>>>>> The SSD drives are Crucial M500 >>>>>> A Ceph user did some benchmarks and found it had good performance >>>>>> https://forum.proxmox.com/threads/ceph-bad-performance- >>>>>> in-qemu-guests.21551/ >>>>>> >>>>>> However, a user comment from 3 years ago on the blog post you linked >>>>>> to says to avoid the Crucial M500 >>>>>> >>>>>> Yet, this performance posting tells that the Crucial M500 is good. >>>>>> https://inside.servers.com/ssd-performance-2017-c4307a92dea >>>>>> >>>>>> On Wed, Oct 18, 2017 at 11:53 AM, Maged Mokhtar <[email protected] >>>>>> > wrote: >>>>>> >>>>>>> Check out the following link: some SSDs perform bad in Ceph due to >>>>>>> sync writes to journal >>>>>>> >>>>>>> https://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to- >>>>>>> test-if-your-ssd-is-suitable-as-a-journal-device/ >>>>>>> >>>>>>> Anther thing that can help is to re-run the rados 32 threads as >>>>>>> stress and view resource usage using atop (or collectl/sar) to check for >>>>>>> %busy cpu and %busy disks to give you an idea of what is holding down >>>>>>> your >>>>>>> cluster..for example: if cpu/disk % are all low then check your >>>>>>> network/switches. If disk %busy is high (90%) for all disks then your >>>>>>> disks are the bottleneck: which either means you have SSDs that are not >>>>>>> suitable for Ceph or you have too few disks (which i doubt is the >>>>>>> case). If >>>>>>> only 1 disk %busy is high, there may be something wrong with this disk >>>>>>> should be removed. >>>>>>> >>>>>>> Maged >>>>>>> >>>>>>> On 2017-10-18 18:13, Russell Glaue wrote: >>>>>>> >>>>>>> In my previous post, in one of my points I was wondering if the >>>>>>> request size would increase if I enabled jumbo packets. currently it is >>>>>>> disabled. >>>>>>> >>>>>>> @jdillama: The qemu settings for both these two guest machines, with >>>>>>> RAID/LVM and Ceph/rbd images, are the same. I am not thinking that >>>>>>> changing >>>>>>> the qemu settings of "min_io_size=<limited to 16bits>,opt_io_size=<RBD >>>>>>> image object size>" will directly address the issue. >>>>>>> >>>>>>> @mmokhtar: Ok. So you suggest the request size is the result of the >>>>>>> problem and not the cause of the problem. meaning I should go after a >>>>>>> different issue. >>>>>>> >>>>>>> I have been trying to get write speeds up to what people on this >>>>>>> mail list are discussing. >>>>>>> It seems that for our configuration, as it matches others, we should >>>>>>> be getting about 70MB/s write speed. >>>>>>> But we are not getting that. >>>>>>> Single writes to disk are lucky to get 5MB/s to 6MB/s, but are >>>>>>> typically 1MB/s to 2MB/s. >>>>>>> Monitoring the entire Ceph cluster (using >>>>>>> http://cephdash.crapworks.de/), I have seen very rare momentary >>>>>>> spikes up to 30MB/s. >>>>>>> >>>>>>> My storage network is connected via a 10Gb switch >>>>>>> I have 4 storage servers with a LSI Logic MegaRAID SAS 2208 >>>>>>> controller >>>>>>> Each storage server has 9 1TB SSD drives, each drive as 1 osd (no >>>>>>> RAID) >>>>>>> Each drive is one LVM group, with two volumes - one volume for the >>>>>>> osd, one volume for the journal >>>>>>> Each osd is formatted with xfs >>>>>>> The crush map is simple: default->rack->[host[1..4]->osd] with an >>>>>>> evenly distributed weight >>>>>>> The redundancy is triple replication >>>>>>> >>>>>>> While I have read comments that having the osd and journal on the >>>>>>> same disk decreases write speed, I have also read that once past 8 OSDs >>>>>>> per >>>>>>> node this is the recommended configuration, however this is also the >>>>>>> reason >>>>>>> why SSD drives are used exclusively for OSDs in the storage nodes. >>>>>>> None-the-less, I was still expecting write speeds to be above >>>>>>> 30MB/s, not below 6MB/s. >>>>>>> Even at 12x slower than the RAID, using my previously posted iostat >>>>>>> data set, I should be seeing write speeds that average 10MB/s, not >>>>>>> 2MB/s. >>>>>>> >>>>>>> In regards to the rados benchmark tests you asked me to run, here is >>>>>>> the output: >>>>>>> >>>>>>> [centos7]# rados bench -p scbench -b 4096 30 write -t 1 >>>>>>> Maintaining 1 concurrent writes of 4096 bytes to objects of size >>>>>>> 4096 for up to 30 seconds or 0 objects >>>>>>> Object prefix: benchmark_data_hamms.sys.cu.cait.org_85049 >>>>>>> sec Cur ops started finished avg MB/s cur MB/s last lat(s) >>>>>>> avg lat(s) >>>>>>> 0 0 0 0 0 0 - >>>>>>> 0 >>>>>>> 1 1 201 200 0.78356 0.78125 0.00522307 >>>>>>> 0.00496574 >>>>>>> 2 1 469 468 0.915303 1.04688 0.00437497 >>>>>>> 0.00426141 >>>>>>> 3 1 741 740 0.964371 1.0625 0.00512853 >>>>>>> 0.0040434 >>>>>>> 4 1 888 887 0.866739 0.574219 0.00307699 >>>>>>> 0.00450177 >>>>>>> 5 1 1147 1146 0.895725 1.01172 0.00376454 >>>>>>> 0.0043559 >>>>>>> 6 1 1325 1324 0.862293 0.695312 0.00459443 >>>>>>> 0.004525 >>>>>>> 7 1 1494 1493 0.83339 0.660156 0.00461002 >>>>>>> 0.00458452 >>>>>>> 8 1 1736 1735 0.847369 0.945312 0.00253971 >>>>>>> 0.00460458 >>>>>>> 9 1 1998 1997 0.866922 1.02344 0.00236573 >>>>>>> 0.00450172 >>>>>>> 10 1 2260 2259 0.882563 1.02344 0.00262179 >>>>>>> 0.00442152 >>>>>>> 11 1 2526 2525 0.896775 1.03906 0.00336914 >>>>>>> 0.00435092 >>>>>>> 12 1 2760 2759 0.898203 0.914062 0.00351827 >>>>>>> 0.00434491 >>>>>>> 13 1 3016 3015 0.906025 1 0.00335703 >>>>>>> 0.00430691 >>>>>>> 14 1 3257 3256 0.908545 0.941406 0.00332344 >>>>>>> 0.00429495 >>>>>>> 15 1 3490 3489 0.908644 0.910156 0.00318815 >>>>>>> 0.00426387 >>>>>>> 16 1 3728 3727 0.909952 0.929688 0.0032881 >>>>>>> 0.00428895 >>>>>>> 17 1 3986 3985 0.915703 1.00781 0.00274809 >>>>>>> 0.0042614 >>>>>>> 18 1 4250 4249 0.922116 1.03125 0.00287411 >>>>>>> 0.00423214 >>>>>>> 19 1 4505 4504 0.926003 0.996094 0.00375435 >>>>>>> 0.00421442 >>>>>>> 2017-10-18 10:56:31.267173 min lat: 0.00181259 max lat: 0.270553 avg >>>>>>> lat: 0.00420118 >>>>>>> sec Cur ops started finished avg MB/s cur MB/s last lat(s) >>>>>>> avg lat(s) >>>>>>> 20 1 4757 4756 0.928915 0.984375 0.00463972 >>>>>>> 0.00420118 >>>>>>> 21 1 5009 5008 0.93155 0.984375 0.00360065 >>>>>>> 0.00418937 >>>>>>> 22 1 5235 5234 0.929329 0.882812 0.00626214 >>>>>>> 0.004199 >>>>>>> 23 1 5500 5499 0.933925 1.03516 0.00466584 >>>>>>> 0.00417836 >>>>>>> 24 1 5708 5707 0.928861 0.8125 0.00285727 >>>>>>> 0.00420146 >>>>>>> 25 0 5964 5964 0.931858 1.00391 0.00417383 >>>>>>> 0.0041881 >>>>>>> 26 1 6216 6215 0.933722 0.980469 0.0041009 >>>>>>> 0.00417915 >>>>>>> 27 1 6481 6480 0.937474 1.03516 0.00307484 >>>>>>> 0.00416118 >>>>>>> 28 1 6745 6744 0.940819 1.03125 0.00266329 >>>>>>> 0.00414777 >>>>>>> 29 1 7003 7002 0.943124 1.00781 0.00305905 >>>>>>> 0.00413758 >>>>>>> 30 1 7271 7270 0.946578 1.04688 0.00391017 >>>>>>> 0.00412238 >>>>>>> Total time run: 30.006060 >>>>>>> Total writes made: 7272 >>>>>>> Write size: 4096 >>>>>>> Object size: 4096 >>>>>>> Bandwidth (MB/sec): 0.946684 >>>>>>> Stddev Bandwidth: 0.123762 >>>>>>> Max bandwidth (MB/sec): 1.0625 >>>>>>> Min bandwidth (MB/sec): 0.574219 >>>>>>> Average IOPS: 242 >>>>>>> Stddev IOPS: 31 >>>>>>> Max IOPS: 272 >>>>>>> Min IOPS: 147 >>>>>>> Average Latency(s): 0.00412247 >>>>>>> Stddev Latency(s): 0.00648437 >>>>>>> Max latency(s): 0.270553 >>>>>>> Min latency(s): 0.00175318 >>>>>>> Cleaning up (deleting benchmark objects) >>>>>>> Clean up completed and total clean up time :29.069423 >>>>>>> >>>>>>> [centos7]# rados bench -p scbench -b 4096 30 write -t 32 >>>>>>> Maintaining 32 concurrent writes of 4096 bytes to objects of size >>>>>>> 4096 for up to 30 seconds or 0 objects >>>>>>> Object prefix: benchmark_data_hamms.sys.cu.cait.org_86076 >>>>>>> sec Cur ops started finished avg MB/s cur MB/s last lat(s) >>>>>>> avg lat(s) >>>>>>> 0 0 0 0 0 0 - >>>>>>> 0 >>>>>>> 1 32 3013 2981 11.6438 11.6445 0.00247906 >>>>>>> 0.00572026 >>>>>>> 2 32 5349 5317 10.3834 9.125 0.00246662 >>>>>>> 0.00932016 >>>>>>> 3 32 5707 5675 7.3883 1.39844 0.00389774 >>>>>>> 0.0156726 >>>>>>> 4 32 5895 5863 5.72481 0.734375 1.13137 >>>>>>> 0.0167946 >>>>>>> 5 32 6869 6837 5.34068 3.80469 0.0027652 >>>>>>> 0.0226577 >>>>>>> 6 32 8901 8869 5.77306 7.9375 0.0053211 >>>>>>> 0.0216259 >>>>>>> 7 32 10800 10768 6.00785 7.41797 0.00358187 >>>>>>> 0.0207418 >>>>>>> 8 32 11825 11793 5.75728 4.00391 0.00217575 >>>>>>> 0.0215494 >>>>>>> 9 32 12941 12909 5.6019 4.35938 0.00278512 >>>>>>> 0.0220567 >>>>>>> 10 32 13317 13285 5.18849 1.46875 0.0034973 >>>>>>> 0.0240665 >>>>>>> 11 32 16189 16157 5.73653 11.2188 0.00255841 >>>>>>> 0.0212708 >>>>>>> 12 32 16749 16717 5.44077 2.1875 0.00330334 >>>>>>> 0.0215915 >>>>>>> 13 32 16756 16724 5.02436 0.0273438 0.00338994 >>>>>>> 0.021849 >>>>>>> 14 32 17908 17876 4.98686 4.5 0.00402598 >>>>>>> 0.0244568 >>>>>>> 15 32 17936 17904 4.66171 0.109375 0.00375799 >>>>>>> 0.0245545 >>>>>>> 16 32 18279 18247 4.45409 1.33984 0.00483873 >>>>>>> 0.0267929 >>>>>>> 17 32 18372 18340 4.21346 0.363281 0.00505187 >>>>>>> 0.0275887 >>>>>>> 18 32 19403 19371 4.20309 4.02734 0.00545154 >>>>>>> 0.029348 >>>>>>> 19 31 19845 19814 4.07295 1.73047 0.00254726 >>>>>>> 0.0306775 >>>>>>> 2017-10-18 10:57:58.160536 min lat: 0.0015005 max lat: 2.27707 avg >>>>>>> lat: 0.0307559 >>>>>>> sec Cur ops started finished avg MB/s cur MB/s last lat(s) >>>>>>> avg lat(s) >>>>>>> 20 31 20401 20370 3.97788 2.17188 0.00307238 >>>>>>> 0.0307559 >>>>>>> 21 32 21338 21306 3.96254 3.65625 0.00464563 >>>>>>> 0.0312288 >>>>>>> 22 32 23057 23025 4.0876 6.71484 0.00296295 >>>>>>> 0.0299267 >>>>>>> 23 32 23057 23025 3.90988 0 - >>>>>>> 0.0299267 >>>>>>> 24 32 23803 23771 3.86837 1.45703 0.00301471 >>>>>>> 0.0312804 >>>>>>> 25 32 24112 24080 3.76191 1.20703 0.00191063 >>>>>>> 0.0331462 >>>>>>> 26 31 25303 25272 3.79629 4.65625 0.00794399 >>>>>>> 0.0329129 >>>>>>> 27 32 28803 28771 4.16183 13.668 0.0109817 >>>>>>> 0.0297469 >>>>>>> 28 32 29592 29560 4.12325 3.08203 0.00188185 >>>>>>> 0.0301911 >>>>>>> 29 32 30595 30563 4.11616 3.91797 0.00379099 >>>>>>> 0.0296794 >>>>>>> 30 32 31031 30999 4.03572 1.70312 0.00283347 >>>>>>> 0.0302411 >>>>>>> Total time run: 30.822350 >>>>>>> Total writes made: 31032 >>>>>>> Write size: 4096 >>>>>>> Object size: 4096 >>>>>>> Bandwidth (MB/sec): 3.93282 >>>>>>> Stddev Bandwidth: 3.66265 >>>>>>> Max bandwidth (MB/sec): 13.668 >>>>>>> Min bandwidth (MB/sec): 0 >>>>>>> Average IOPS: 1006 >>>>>>> Stddev IOPS: 937 >>>>>>> Max IOPS: 3499 >>>>>>> Min IOPS: 0 >>>>>>> Average Latency(s): 0.0317779 >>>>>>> Stddev Latency(s): 0.164076 >>>>>>> Max latency(s): 2.27707 >>>>>>> Min latency(s): 0.0013848 >>>>>>> Cleaning up (deleting benchmark objects) >>>>>>> Clean up completed and total clean up time :20.166559 >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Wed, Oct 18, 2017 at 8:51 AM, Maged Mokhtar <[email protected] >>>>>>> > wrote: >>>>>>> >>>>>>>> First a general comment: local RAID will be faster than Ceph for a >>>>>>>> single threaded (queue depth=1) io operation test. A single thread Ceph >>>>>>>> client will see at best same disk speed for reads and for writes 4-6 >>>>>>>> times >>>>>>>> slower than single disk. Not to mention the latency of local disks will >>>>>>>> much better. Where Ceph shines is when you have many concurrent ios, it >>>>>>>> scales whereas RAID will decrease speed per client as you add more. >>>>>>>> >>>>>>>> Having said that, i would recommend running rados/rbd bench-write >>>>>>>> and measure 4k iops at 1 and 32 threads to get a better idea of how >>>>>>>> your >>>>>>>> cluster performs: >>>>>>>> >>>>>>>> ceph osd pool create testpool 256 256 >>>>>>>> rados bench -p testpool -b 4096 30 write -t 1 >>>>>>>> rados bench -p testpool -b 4096 30 write -t 32 >>>>>>>> ceph osd pool delete testpool testpool --yes-i-really-really-mean-it >>>>>>>> >>>>>>>> rbd bench-write test-image --io-threads=1 --io-size 4096 >>>>>>>> --io-pattern rand --rbd_cache=false >>>>>>>> rbd bench-write test-image --io-threads=32 --io-size 4096 >>>>>>>> --io-pattern rand --rbd_cache=false >>>>>>>> >>>>>>>> I think the request size difference you see is due to the io >>>>>>>> scheduler in the case of local disks having more ios to re-group so >>>>>>>> has a >>>>>>>> better chance in generating larger requests. Depending on your kernel, >>>>>>>> the >>>>>>>> io scheduler may be different for rbd (blq-mq) vs sdx (cfq) but again i >>>>>>>> would think the request size is a result not a cause. >>>>>>>> >>>>>>>> Maged >>>>>>>> >>>>>>>> On 2017-10-17 23:12, Russell Glaue wrote: >>>>>>>> >>>>>>>> I am running ceph jewel on 5 nodes with SSD OSDs. >>>>>>>> I have an LVM image on a local RAID of spinning disks. >>>>>>>> I have an RBD image on in a pool of SSD disks. >>>>>>>> Both disks are used to run an almost identical CentOS 7 system. >>>>>>>> Both systems were installed with the same kickstart, though the >>>>>>>> disk partitioning is different. >>>>>>>> >>>>>>>> I want to make writes on the the ceph image faster. For example, >>>>>>>> lots of writes to MySQL (via MySQL replication) on a ceph SSD image are >>>>>>>> about 10x slower than on a spindle RAID disk image. The MySQL server on >>>>>>>> ceph rbd image has a hard time keeping up in replication. >>>>>>>> >>>>>>>> So I wanted to test writes on these two systems >>>>>>>> I have a 10GB compressed (gzip) file on both servers. >>>>>>>> I simply gunzip the file on both systems, while running iostat. >>>>>>>> >>>>>>>> The primary difference I see in the results is the average size of >>>>>>>> the request to the disk. >>>>>>>> CentOS7-lvm-raid-sata writes a lot faster to disk, and the size of >>>>>>>> the request is about 40x, but the number of writes per second is about >>>>>>>> the >>>>>>>> same >>>>>>>> This makes me want to conclude that the smaller size of the request >>>>>>>> for CentOS7-ceph-rbd-ssd system is the cause of it being slow. >>>>>>>> >>>>>>>> >>>>>>>> How can I make the size of the request larger for ceph rbd images, >>>>>>>> so I can increase the write throughput? >>>>>>>> Would this be related to having jumbo packets enabled in my ceph >>>>>>>> storage network? >>>>>>>> >>>>>>>> >>>>>>>> Here is a sample of the results: >>>>>>>> >>>>>>>> [CentOS7-lvm-raid-sata] >>>>>>>> $ gunzip large10gFile.gz & >>>>>>>> $ iostat -x vg_root-lv_var -d 5 -m -N >>>>>>>> Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s >>>>>>>> avgrq-sz avgqu-sz await r_await w_await svctm %util >>>>>>>> ... >>>>>>>> vg_root-lv_var 0.00 0.00 30.60 452.20 13.60 222.15 >>>>>>>> 1000.04 8.69 14.05 0.99 14.93 2.07 100.04 >>>>>>>> vg_root-lv_var 0.00 0.00 88.20 182.00 39.20 89.43 >>>>>>>> 974.95 4.65 9.82 0.99 14.10 3.70 100.00 >>>>>>>> vg_root-lv_var 0.00 0.00 75.45 278.24 33.53 136.70 >>>>>>>> 985.73 4.36 33.26 1.34 41.91 0.59 20.84 >>>>>>>> vg_root-lv_var 0.00 0.00 111.60 181.80 49.60 89.34 >>>>>>>> 969.84 2.60 8.87 0.81 13.81 0.13 3.90 >>>>>>>> vg_root-lv_var 0.00 0.00 68.40 109.60 30.40 53.63 >>>>>>>> 966.87 1.51 8.46 0.84 13.22 0.80 14.16 >>>>>>>> ... >>>>>>>> >>>>>>>> [CentOS7-ceph-rbd-ssd] >>>>>>>> $ gunzip large10gFile.gz & >>>>>>>> $ iostat -x vg_root-lv_data -d 5 -m -N >>>>>>>> Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s >>>>>>>> avgrq-sz avgqu-sz await r_await w_await svctm %util >>>>>>>> ... >>>>>>>> vg_root-lv_data 0.00 0.00 46.40 167.80 0.88 1.46 >>>>>>>> 22.36 1.23 5.66 2.47 6.54 4.52 96.82 >>>>>>>> vg_root-lv_data 0.00 0.00 16.60 55.20 0.36 0.14 >>>>>>>> 14.44 0.99 13.91 9.12 15.36 13.71 98.46 >>>>>>>> vg_root-lv_data 0.00 0.00 69.00 173.80 1.34 1.32 >>>>>>>> 22.48 1.25 5.19 3.77 5.75 3.94 95.68 >>>>>>>> vg_root-lv_data 0.00 0.00 74.40 293.40 1.37 1.47 >>>>>>>> 15.83 1.22 3.31 2.06 3.63 2.54 93.26 >>>>>>>> vg_root-lv_data 0.00 0.00 90.80 359.00 1.96 3.41 >>>>>>>> 24.45 1.63 3.63 1.94 4.05 2.10 94.38 >>>>>>>> ... >>>>>>>> >>>>>>>> [iostat key] >>>>>>>> w/s == The number (after merges) of write requests completed per >>>>>>>> second for the device. >>>>>>>> wMB/s == The number of sectors (kilobytes, megabytes) written to >>>>>>>> the device per second. >>>>>>>> avgrq-sz == The average size (in kilobytes) of the requests that >>>>>>>> were issued to the device. >>>>>>>> avgqu-sz == The average queue length of the requests that were >>>>>>>> issued to the device. >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> ceph-users mailing list >>>>>>>> [email protected] >>>>>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> ceph-users mailing list >>>> [email protected] >>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>>> >>> >>
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